onsemi NCP1351LEDGEVB, Constant Current LED Driver Evaluation Board Evaluation Board for NCP1351BDR2G for Constant

The NCP1351 controller provides for a low cost, variable frequency, flyback converter. it incorporates a very low quiescent current allowing for high value resistors to be used as a start-up circuit direct from the HV rail. The design comprises and input pi-filter, bridge rectifier (using low cost 1N4007 diodes), bulk capacitors and line inductor in filter arrangement, the power stage, rectifier diode and smoothing capacitors. Feedback is CVCC, constant current drive for the LED's with a constant voltage in the event of an open circuit output. In order to stay below IEC6100-3-2 Class C, the design has been optimized at <25 W, so assuming 80% efficiency the maximum output power is ∼20 W.